docs: def maps_json():
      """
      Generates a json object which serves as bridge between
      the web interface and the map source collection.
  
      All attributes relevant for openlayers are converted into
      JSON and served through this route.
  
      Returns:
          Response: All map sources as JSON object.
      """
      map_sources = {
          id: {
                  "id": map_source.id,
                  "name": map_source.name,
                  "folder": map_source.folder,
                  "min_zoom": map_source.min_zoom,
                  "max_zoom": map_source.max_zoom,
                  "layers": [
                      {
                          "min_zoom": layer.min_zoom,
                          "max_zoom": layer.max_zoom,
                          "tile_url": layer.tile_url.replace("$", ""),
                      } for layer in map_source.layers
                      ]
  
              } for id, map_source in app.config["mapsources"].items()
          }
      return jsonify(map_sources)